diff options
Diffstat (limited to 'drivers/thermal/st/stm_thermal.c')
| -rw-r--r-- | drivers/thermal/st/stm_thermal.c | 602 |
1 files changed, 602 insertions, 0 deletions
diff --git a/drivers/thermal/st/stm_thermal.c b/drivers/thermal/st/stm_thermal.c new file mode 100644 index 000000000..78feb802a --- /dev/null +++ b/drivers/thermal/st/stm_thermal.c @@ -0,0 +1,602 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) STMicroelectronics 2018 - All Rights Reserved + * Author: David Hernandez Sanchez <david.hernandezsanchez@st.com> for + * STMicroelectronics. + */ + +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/thermal.h> + +#include "../thermal_core.h" +#include "../thermal_hwmon.h" + +/* DTS register offsets */ +#define DTS_CFGR1_OFFSET 0x0 +#define DTS_T0VALR1_OFFSET 0x8 +#define DTS_RAMPVALR_OFFSET 0X10 +#define DTS_ITR1_OFFSET 0x14 +#define DTS_DR_OFFSET 0x1C +#define DTS_SR_OFFSET 0x20 +#define DTS_ITENR_OFFSET 0x24 +#define DTS_ICIFR_OFFSET 0x28 + +/* DTS_CFGR1 register mask definitions */ +#define HSREF_CLK_DIV_MASK GENMASK(30, 24) +#define TS1_SMP_TIME_MASK GENMASK(19, 16) +#define TS1_INTRIG_SEL_MASK GENMASK(11, 8) + +/* DTS_T0VALR1 register mask definitions */ +#define TS1_T0_MASK GENMASK(17, 16) +#define TS1_FMT0_MASK GENMASK(15, 0) + +/* DTS_RAMPVALR register mask definitions */ +#define TS1_RAMP_COEFF_MASK GENMASK(15, 0) + +/* DTS_ITR1 register mask definitions */ +#define TS1_HITTHD_MASK GENMASK(31, 16) +#define TS1_LITTHD_MASK GENMASK(15, 0) + +/* DTS_DR register mask definitions */ +#define TS1_MFREQ_MASK GENMASK(15, 0) + +/* DTS_ITENR register mask definitions */ +#define ITENR_MASK (GENMASK(2, 0) | GENMASK(6, 4)) + +/* DTS_ICIFR register mask definitions */ +#define ICIFR_MASK (GENMASK(2, 0) | GENMASK(6, 4)) + +/* Less significant bit position definitions */ +#define TS1_T0_POS 16 +#define TS1_HITTHD_POS 16 +#define TS1_LITTHD_POS 0 +#define HSREF_CLK_DIV_POS 24 + +/* DTS_CFGR1 bit definitions */ +#define TS1_EN BIT(0) +#define TS1_START BIT(4) +#define REFCLK_SEL BIT(20) +#define REFCLK_LSE REFCLK_SEL +#define Q_MEAS_OPT BIT(21) +#define CALIBRATION_CONTROL Q_MEAS_OPT + +/* DTS_SR bit definitions */ +#define TS_RDY BIT(15) +/* Bit definitions below are common for DTS_SR, DTS_ITENR and DTS_CIFR */ +#define HIGH_THRESHOLD BIT(2) +#define LOW_THRESHOLD BIT(1) + +/* Constants */ +#define ADJUST 100 +#define ONE_MHZ 1000000 +#define POLL_TIMEOUT 5000 +#define STARTUP_TIME 40 +#define TS1_T0_VAL0 30000 /* 30 celsius */ +#define TS1_T0_VAL1 130000 /* 130 celsius */ +#define NO_HW_TRIG 0 +#define SAMPLING_TIME 15 + +struct stm_thermal_sensor { + struct device *dev; + struct thermal_zone_device *th_dev; + enum thermal_device_mode mode; + struct clk *clk; + unsigned int low_temp_enabled; + unsigned int high_temp_enabled; + int irq; + void __iomem *base; + int t0, fmt0, ramp_coeff; +}; + +static int stm_enable_irq(struct stm_thermal_sensor *sensor) +{ + u32 value; + + dev_dbg(sensor->dev, "low:%d high:%d\n", sensor->low_temp_enabled, + sensor->high_temp_enabled); + + /* Disable IT generation for low and high thresholds */ + value = readl_relaxed(sensor->base + DTS_ITENR_OFFSET); + value &= ~(LOW_THRESHOLD | HIGH_THRESHOLD); + + if (sensor->low_temp_enabled) + value |= HIGH_THRESHOLD; + + if (sensor->high_temp_enabled) + value |= LOW_THRESHOLD; + + /* Enable interrupts */ + writel_relaxed(value, sensor->base + DTS_ITENR_OFFSET); + + return 0; +} + +static irqreturn_t stm_thermal_irq_handler(int irq, void *sdata) +{ + struct stm_thermal_sensor *sensor = sdata; + + dev_dbg(sensor->dev, "sr:%d\n", + readl_relaxed(sensor->base + DTS_SR_OFFSET)); + + thermal_zone_device_update(sensor->th_dev, THERMAL_EVENT_UNSPECIFIED); + + stm_enable_irq(sensor); + + /* Acknoledge all DTS irqs */ + writel_relaxed(ICIFR_MASK, sensor->base + DTS_ICIFR_OFFSET); + + return IRQ_HANDLED; +} + +static int stm_sensor_power_on(struct stm_thermal_sensor *sensor) +{ + int ret; + u32 value; + + /* Enable sensor */ + value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET); + value |= TS1_EN; + writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET); + + /* + * The DTS block can be enabled by setting TSx_EN bit in + * DTS_CFGRx register. It requires a startup time of + * 40μs. Use 5 ms as arbitrary timeout. + */ + ret = readl_poll_timeout(sensor->base + DTS_SR_OFFSET, + value, (value & TS_RDY), + STARTUP_TIME, POLL_TIMEOUT); + if (ret) + return ret; + + /* Start continuous measuring */ + value = readl_relaxed(sensor->base + + DTS_CFGR1_OFFSET); + value |= TS1_START; + writel_relaxed(value, sensor->base + + DTS_CFGR1_OFFSET); + + sensor->mode = THERMAL_DEVICE_ENABLED; + + return 0; +} + +static int stm_sensor_power_off(struct stm_thermal_sensor *sensor) +{ + u32 value; + + sensor->mode = THERMAL_DEVICE_DISABLED; + + /* Stop measuring */ + value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET); + value &= ~TS1_START; + writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET); + + /* Ensure stop is taken into account */ + usleep_range(STARTUP_TIME, POLL_TIMEOUT); + + /* Disable sensor */ + value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET); + value &= ~TS1_EN; + writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET); + + /* Ensure disable is taken into account */ + return readl_poll_timeout(sensor->base + DTS_SR_OFFSET, value, + !(value & TS_RDY), + STARTUP_TIME, POLL_TIMEOUT); +} + +static int stm_thermal_calibration(struct stm_thermal_sensor *sensor) +{ + u32 value, clk_freq; + u32 prescaler; + + /* Figure out prescaler value for PCLK during calibration */ + clk_freq = clk_get_rate(sensor->clk); + if (!clk_freq) + return -EINVAL; + + prescaler = 0; + clk_freq /= ONE_MHZ; + if (clk_freq) { + while (prescaler <= clk_freq) + prescaler++; + } + + value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET); + + /* Clear prescaler */ + value &= ~HSREF_CLK_DIV_MASK; + + /* Set prescaler. pclk_freq/prescaler < 1MHz */ + value |= (prescaler << HSREF_CLK_DIV_POS); + + /* Select PCLK as reference clock */ + value &= ~REFCLK_SEL; + + /* Set maximal sampling time for better precision */ + value |= TS1_SMP_TIME_MASK; + + /* Measure with calibration */ + value &= ~CALIBRATION_CONTROL; + + /* select trigger */ + value &= ~TS1_INTRIG_SEL_MASK; + value |= NO_HW_TRIG; + + writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET); + + return 0; +} + +/* Fill in DTS structure with factory sensor values */ +static int stm_thermal_read_factory_settings(struct stm_thermal_sensor *sensor) +{ + /* Retrieve engineering calibration temperature */ + sensor->t0 = readl_relaxed(sensor->base + DTS_T0VALR1_OFFSET) & + TS1_T0_MASK; + if (!sensor->t0) + sensor->t0 = TS1_T0_VAL0; + else + sensor->t0 = TS1_T0_VAL1; + + /* Retrieve fmt0 and put it on Hz */ + sensor->fmt0 = ADJUST * (readl_relaxed(sensor->base + + DTS_T0VALR1_OFFSET) & TS1_FMT0_MASK); + + /* Retrieve ramp coefficient */ + sensor->ramp_coeff = readl_relaxed(sensor->base + DTS_RAMPVALR_OFFSET) & + TS1_RAMP_COEFF_MASK; + + if (!sensor->fmt0 || !sensor->ramp_coeff) { + dev_err(sensor->dev, "%s: wrong setting\n", __func__); + return -EINVAL; + } + + dev_dbg(sensor->dev, "%s: T0 = %doC, FMT0 = %dHz, RAMP_COEFF = %dHz/oC", + __func__, sensor->t0, sensor->fmt0, sensor->ramp_coeff); + + return 0; +} + +static int stm_thermal_calculate_threshold(struct stm_thermal_sensor *sensor, + int temp, u32 *th) +{ + int freqM; + + /* Figure out the CLK_PTAT frequency for a given temperature */ + freqM = ((temp - sensor->t0) * sensor->ramp_coeff) / 1000 + + sensor->fmt0; + + /* Figure out the threshold sample number */ + *th = clk_get_rate(sensor->clk) * SAMPLING_TIME / freqM; + if (!*th) + return -EINVAL; + + dev_dbg(sensor->dev, "freqM=%d Hz, threshold=0x%x", freqM, *th); + + return 0; +} + +/* Disable temperature interrupt */ +static int stm_disable_irq(struct stm_thermal_sensor *sensor) +{ + u32 value; + + /* Disable IT generation */ + value = readl_relaxed(sensor->base + DTS_ITENR_OFFSET); + value &= ~ITENR_MASK; + writel_relaxed(value, sensor->base + DTS_ITENR_OFFSET); + + return 0; +} + +static int stm_thermal_set_trips(struct thermal_zone_device *tz, int low, int high) +{ + struct stm_thermal_sensor *sensor = tz->devdata; + u32 itr1, th; + int ret; + + dev_dbg(sensor->dev, "set trips %d <--> %d\n", low, high); + + /* Erase threshold content */ + itr1 = readl_relaxed(sensor->base + DTS_ITR1_OFFSET); + itr1 &= ~(TS1_LITTHD_MASK | TS1_HITTHD_MASK); + + /* + * Disable low-temp if "low" is too small. As per thermal framework + * API, we use -INT_MAX rather than INT_MIN. + */ + + if (low > -INT_MAX) { + sensor->low_temp_enabled = 1; + /* add 0.5 of hysteresis due to measurement error */ + ret = stm_thermal_calculate_threshold(sensor, low - 500, &th); + if (ret) + return ret; + + itr1 |= (TS1_HITTHD_MASK & (th << TS1_HITTHD_POS)); + } else { + sensor->low_temp_enabled = 0; + } + + /* Disable high-temp if "high" is too big. */ + if (high < INT_MAX) { + sensor->high_temp_enabled = 1; + ret = stm_thermal_calculate_threshold(sensor, high, &th); + if (ret) + return ret; + + itr1 |= (TS1_LITTHD_MASK & (th << TS1_LITTHD_POS)); + } else { + sensor->high_temp_enabled = 0; + } + + /* Write new threshod values*/ + writel_relaxed(itr1, sensor->base + DTS_ITR1_OFFSET); + + return 0; +} + +/* Callback to get temperature from HW */ +static int stm_thermal_get_temp(struct thermal_zone_device *tz, int *temp) +{ + struct stm_thermal_sensor *sensor = tz->devdata; + u32 periods; + int freqM, ret; + + if (sensor->mode != THERMAL_DEVICE_ENABLED) + return -EAGAIN; + + /* Retrieve the number of periods sampled */ + ret = readl_relaxed_poll_timeout(sensor->base + DTS_DR_OFFSET, periods, + (periods & TS1_MFREQ_MASK), + STARTUP_TIME, POLL_TIMEOUT); + if (ret) + return ret; + + /* Figure out the CLK_PTAT frequency */ + freqM = (clk_get_rate(sensor->clk) * SAMPLING_TIME) / periods; + if (!freqM) + return -EINVAL; + + /* Figure out the temperature in mili celsius */ + *temp = (freqM - sensor->fmt0) * 1000 / sensor->ramp_coeff + sensor->t0; + + return 0; +} + +/* Registers DTS irq to be visible by GIC */ +static int stm_register_irq(struct stm_thermal_sensor *sensor) +{ + struct device *dev = sensor->dev; + struct platform_device *pdev = to_platform_device(dev); + int ret; + + sensor->irq = platform_get_irq(pdev, 0); + if (sensor->irq < 0) + return sensor->irq; + + ret = devm_request_threaded_irq(dev, sensor->irq, + NULL, + stm_thermal_irq_handler, + IRQF_ONESHOT, + dev->driver->name, sensor); + if (ret) { + dev_err(dev, "%s: Failed to register IRQ %d\n", __func__, + sensor->irq); + return ret; + } + + dev_dbg(dev, "%s: thermal IRQ registered", __func__); + + return 0; +} + +static int stm_thermal_sensor_off(struct stm_thermal_sensor *sensor) +{ + int ret; + + stm_disable_irq(sensor); + + ret = stm_sensor_power_off(sensor); + if (ret) + return ret; + + clk_disable_unprepare(sensor->clk); + + return 0; +} + +static int stm_thermal_prepare(struct stm_thermal_sensor *sensor) +{ + int ret; + + ret = clk_prepare_enable(sensor->clk); + if (ret) + return ret; + + ret = stm_thermal_read_factory_settings(sensor); + if (ret) + goto thermal_unprepare; + + ret = stm_thermal_calibration(sensor); + if (ret) + goto thermal_unprepare; + + return 0; + +thermal_unprepare: + clk_disable_unprepare(sensor->clk); + + return ret; +} + +#ifdef CONFIG_PM_SLEEP +static int stm_thermal_suspend(struct device *dev) +{ + struct stm_thermal_sensor *sensor = dev_get_drvdata(dev); + + return stm_thermal_sensor_off(sensor); +} + +static int stm_thermal_resume(struct device *dev) +{ + int ret; + struct stm_thermal_sensor *sensor = dev_get_drvdata(dev); + + ret = stm_thermal_prepare(sensor); + if (ret) + return ret; + + ret = stm_sensor_power_on(sensor); + if (ret) + return ret; + + thermal_zone_device_update(sensor->th_dev, THERMAL_EVENT_UNSPECIFIED); + stm_enable_irq(sensor); + + return 0; +} +#endif /* CONFIG_PM_SLEEP */ + +static SIMPLE_DEV_PM_OPS(stm_thermal_pm_ops, + stm_thermal_suspend, stm_thermal_resume); + +static const struct thermal_zone_device_ops stm_tz_ops = { + .get_temp = stm_thermal_get_temp, + .set_trips = stm_thermal_set_trips, +}; + +static const struct of_device_id stm_thermal_of_match[] = { + { .compatible = "st,stm32-thermal"}, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, stm_thermal_of_match); + +static int stm_thermal_probe(struct platform_device *pdev) +{ + struct stm_thermal_sensor *sensor; + struct resource *res; + void __iomem *base; + int ret; + + if (!pdev->dev.of_node) { + dev_err(&pdev->dev, "%s: device tree node not found\n", + __func__); + return -EINVAL; + } + + sensor = devm_kzalloc(&pdev->dev, sizeof(*sensor), GFP_KERNEL); + if (!sensor) + return -ENOMEM; + + platform_set_drvdata(pdev, sensor); + + sensor->dev = &pdev->dev; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(base)) + return PTR_ERR(base); + + /* Populate sensor */ + sensor->base = base; + + sensor->clk = devm_clk_get(&pdev->dev, "pclk"); + if (IS_ERR(sensor->clk)) { + dev_err(&pdev->dev, "%s: failed to fetch PCLK clock\n", + __func__); + return PTR_ERR(sensor->clk); + } + + stm_disable_irq(sensor); + + /* Clear irq flags */ + writel_relaxed(ICIFR_MASK, sensor->base + DTS_ICIFR_OFFSET); + + /* Configure and enable HW sensor */ + ret = stm_thermal_prepare(sensor); + if (ret) { + dev_err(&pdev->dev, "Error prepare sensor: %d\n", ret); + return ret; + } + + ret = stm_sensor_power_on(sensor); + if (ret) { + dev_err(&pdev->dev, "Error power on sensor: %d\n", ret); + return ret; + } + + sensor->th_dev = devm_thermal_of_zone_register(&pdev->dev, 0, + sensor, + &stm_tz_ops); + + if (IS_ERR(sensor->th_dev)) { + dev_err(&pdev->dev, "%s: thermal zone sensor registering KO\n", + __func__); + ret = PTR_ERR(sensor->th_dev); + return ret; + } + + /* Register IRQ into GIC */ + ret = stm_register_irq(sensor); + if (ret) + goto err_tz; + + stm_enable_irq(sensor); + + /* + * Thermal_zone doesn't enable hwmon as default, + * enable it here + */ + sensor->th_dev->tzp->no_hwmon = false; + ret = thermal_add_hwmon_sysfs(sensor->th_dev); + if (ret) + goto err_tz; + + dev_info(&pdev->dev, "%s: Driver initialized successfully\n", + __func__); + + return 0; + +err_tz: + return ret; +} + +static int stm_thermal_remove(struct platform_device *pdev) +{ + struct stm_thermal_sensor *sensor = platform_get_drvdata(pdev); + + stm_thermal_sensor_off(sensor); + thermal_remove_hwmon_sysfs(sensor->th_dev); + + return 0; +} + +static struct platform_driver stm_thermal_driver = { + .driver = { + .name = "stm_thermal", + .pm = &stm_thermal_pm_ops, + .of_match_table = stm_thermal_of_match, + }, + .probe = stm_thermal_probe, + .remove = stm_thermal_remove, +}; +module_platform_driver(stm_thermal_driver); + +MODULE_DESCRIPTION("STMicroelectronics STM32 Thermal Sensor Driver"); +MODULE_AUTHOR("David Hernandez Sanchez <david.hernandezsanchez@st.com>"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:stm_thermal"); |